JPH0442769Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a temperature/liquid leak detection line that can be used both to detect abnormal temperature of a detected object and to detect liquid leakage.

<Prior art and its problems> Fire alarms and sensors for detecting liquid leaks are sometimes installed in structures such as buildings and mechanical equipment for fire prevention and flood prevention purposes, but these In order to detect liquid, it is necessary to separately provide a dedicated sensor for each, which poses a problem in that wiring becomes difficult when installing various sensors.
Moreover, most conventional sensors detect abnormalities at a single point, so in order to detect abnormalities over a wide area, a large number of sensors must be installed, and disaster prevention equipment There is also the problem of cost.

The present invention was developed in view of the above-mentioned problems, and detects abnormalities when at least a part of the object to be detected is heated to a temperature higher than a predetermined value or when liquid leaks. The purpose is to enable detection over a wide range with one sensor.

<Means for Solving the Problems> In order to achieve the above purpose, the temperature/liquid leak detection wire of the present invention has a first conductor, an inner braided body and a second conductor on a plastic optical fiber. The cable core is formed by covering a cable core formed by sequentially covering conductors of the above with an external braided body made of a liquid-absorbing thread, and each of the first and second conductors is made of a metal braided body, and The inner braid consists of synthetic fiber yarns.

<Function> The temperature/liquid leakage detection wire of the present invention has a braided body around the outer circumference of the cable core and around the plastic optical fiber, so good air permeability between the outside and the optical fiber is maintained. When at least a part of the object to be detected on which the temperature/leakage detection wire is installed is heated and the temperature of the surrounding air rises, the surrounding air is smoothly guided to the optical fiber part, and the temperature rise is reduced. , is immediately transmitted to the plastic optical fiber, and as a result, when the temperature of the plastic optical fiber reaches the softening temperature or higher, the overheated portion locally softens, contracts, and breaks. For this reason, the optical signal from the light source is no longer transmitted midway through, and an abnormality is detected by a photodetector connected to the plastic optical fiber.

On the other hand, if leakage occurs, the liquid will be absorbed by the external braided body made of liquid-absorbing threads, and the liquid will efficiently spread to the surrounding area due to capillary action. However, since the leaked liquid is efficiently introduced into the core and penetrates the internal braid, the resistance value between the conductors decreases, and the occurrence of liquid leakage is detected by a measuring device connected to the conductors.

Furthermore, since at least one of the conductors is coated on the plastic optical fiber, the cross-sectional area of the sensing wire can be made smaller than when it is provided separately.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a sectional view of a temperature/liquid leak detection line according to an embodiment of the present invention.

The temperature/liquid leakage detection wire 40 of this embodiment has a first conductor 44 made of a metal wire braid, an inner braid 46, and a second conductor made of a metal wire braid on one plastic optical fiber 42. The cable core 49 is formed by sequentially covering the conductor 48 and is covered with an external braided body 50 made of liquid-absorbing thread.

The plastic optical fiber 42 is made of a material that has excellent bending resistance and has the property of softening and shrinking in a certain temperature range when heated, such as a highly flexible material such as methacrylic resin or polystyrene resin. A fiber wire 16 formed by covering a core 12 with a low refractive index cladding 14 such as fluororesin is coated with a protective layer 18 such as black polyethylene.

The internal braided body 46 made of synthetic fiber yarn is as follows:
For example, a braided body made of monofilament polyethylene yarn is used.

Further, the cable core 49 is covered with an external braided body 50 made of a liquid-absorbing yarn, for example, a multifilament Tetoron yarn.

If the temperature/liquid leakage detection line 40 having the above configuration is disposed on the object to be detected, if a part of the object to be detected is overheated and the temperature of the plastic optical fiber 42 reaches the softening temperature or higher, the overheating will occur. Parts soften,
Shrink and break. As a result, the optical signal from the light source is no longer transmitted midway through, and a photodetector connected to the plastic optical fiber 42 detects the abnormality.

On the other hand, if leakage occurs, the conductors 44, 4
Since the resistance value between conductors 44 and 48 decreases,
The occurrence of liquid leakage is detected by a measuring device connected to the

<Effects> As described above, according to the present invention, a liquid-absorbing material is coated on a cable core formed by sequentially covering a plastic optical fiber with a first conductor, an internal braided body, and a second conductor. It is constructed by covering an outer braided body made of yarn, each of the first and second conductors is made of a metal braided body, and the inner braided body is made of a synthetic fiber yarn. Even without separately providing a liquid leakage sensor and a temperature/liquid leakage detection line, it is possible to reliably detect both the occurrence of fire and the occurrence of liquid leakage using only this temperature/liquid leakage detection line.

Therefore, if a temperature/liquid leakage detection line is installed inside a building or equipment, and a photodetector, resistance measuring device, alarm, etc. is connected to it, abnormality detection of temperature and liquid leakage can be performed. A dual-purpose detection system can be configured, so
Installing sensors is also advantageous, and the cost of disaster prevention equipment can be reduced, making it useful for fire and flood prevention.

In particular, in this structure, both the outer periphery of the cable core and the plastic optical fiber are made of braided material, so good air permeability between the outside and the optical fiber is maintained, and the temperature/leakage detection wire is When at least a portion of the installed object to be detected becomes overheated and the temperature of the surrounding air increases, the surrounding air is smoothly guided to the optical fiber section, and the temperature increase is immediately transmitted to the plastic optical fiber. As a result, abnormal temperature detection can be performed quickly and accurately.

In addition, since the external braided body is made of liquid-absorbing threads, any leakage liquid is efficiently absorbed by the external braided body, and the absorbed liquid is efficiently spread to the surrounding area by capillary action, thereby increasing the distance between the conductors. Even if the distance is far away, the leakage liquid is efficiently introduced into the core and the resistance value between the conductors is reduced, so that the occurrence of liquid leakage can be detected quickly and accurately.

Furthermore, since at least one of the conductors is coated on the plastic optical fiber, the cross-sectional area of the detection wire can be made smaller than when it is provided separately.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a temperature/liquid leak detection line according to an embodiment of the present invention. 40...Temperature/leak detection wire, 42...Plastic optical fiber, 44, 48...First and second conductors, 46...Inner braided body, 49...Cable core, 50...Outer braid body.

Claims (1)

[Claims for Utility Model Registration] (1) A cable core consisting of a plastic optical fiber coated with a first conductor, an internal braided body, and a second conductor in sequence is coated with a liquid-absorbing thread. The first and second conductors are made of a metal braid, and the inner braid is made of a synthetic fiber thread. line. (2) The temperature/liquid leak detection wire according to claim 1, wherein the synthetic fiber yarn of the internal braided body is a monofilament polyethylene yarn.